This new implementation uses a special mimetype to tag data copied from
the guest, instead of using flags. This should make it easier to
implement asynchronous transfers in the future. Also, it's simpler to
understand and less error-prone.
The pid is included in the mimetype in order to distinguish between
different instances of looking glass: you might want to copy between
two different VMs, for example.
One of the major issues with the old tracking code is a data race
between the cursor thread updating g_cursor.guest and the
app_handleMouseBasic function. Specifically, the latter may have
sent mouse input via spice that has not been processed by the guest
and updated g_cursor.guest, but the guest may overwrite g_cursor.guest
to a previous state before the input is processed. This causes some
movements to be doubled. Eventually, the cursor positions will
synchronize, but this nevertheless causes a lot of jitter.
In this commit, we introduce a new field g_cursor.projected, which
is unambiguously the position of the cursor after taking into account
all the input already sent via spice. This is synced up to the guest
cursor upon entering the window and when the host restarts. Afterwards,
all mouse movements will be based on this position. This eliminates
all cursor jitter as far as I could tell.
Also, the cursor is now synced to the host position when exiting
capture mode.
A downside of this commit is that if the 1:1 movement patch is not
correctly applied, the cursor position would be wildly off instead
of simply jittering, but that is an unsupported configuration and
should not matter.
Also unsupported is when an application in guest moves the cursor
programmatically and bypassing spice. When using those applications,
capture mode must be on. Before this commit, we try to move the guest
cursor back to where it should be, but it's inherently fragile and
may lead to scenarios such as wild movements in first-person shooters.
We used to test for the EGL_KHR_platform_base and EGL_EXT_platform_base,
but those only really signal the availability of eglGetPlatformDisplay(EXT)
functions, not whether the constant EGL_PLATFORM_WAYLAND_KHR or
EGL_PLATFORM_WAYLAND_EXT is accepted by their respective functions.
Instead, we switch to test for the extensions that tells us whether the
Wayland platform is supported.
Using a macro ENABLE_OPENGL just like ENABLE_EGL to optionally remove
OpenGL implementation code. This is mostly because on Wayland it's just
a rehash of the EGL code (as EGL is the only way to create OpenGL
contexts on Wayland).
Before this, copying rich text ends up with a lot of funky behaviour,
for example:
* copying text from Discord shows up as HTML unless pasted into a text
editor first
* copying text from Firefox shows up as the single letter h
This commit fixes all the above issues.
Due to the change in logic, we now use the first text format offered
instead of the last, which is almost certainly the preferred form.
Doing this gets us proper Unicode support, or Unicode characters would
end up as escapes of the form \uXXXX (this is used in the fallback
forms for applications without UTF-8 support).
We are forced to use accelerated movement in regular mode as that is how the
host machine cursor moves and we want the cursors to line up (since Wayland
cannot do warps). To avoid a change in sensitivity when toggling capture
mode on/off, we should use accelerated deltas for capture mode as well,
unless the user explicitly asks for raw input with input:rawMouse.
It appears that Wayland pointer motion handlers are called even when relative
mouse mode is enabled. The events they generate break first-person games.
This commit disables those handlers when relative mouse is enabled.
zwp_relative_pointer_manager_v1 and zwp_pointer_constraints_v1 are
supported by GNOME/KDE/sway (and most other compositors), but they are
not a required part of the protocol.
Some users also run software in one-off nested compositors like cage[0]
for an extra layer of isolation; cage, at least, does not support
pointer captures.
This commit makes Looking Glass warn when an optional protocol is
unsupported, and fail if a required one is missing. Pointer grab paths
have a new guard against the aforementioned protocols being missing.
[0]: https://github.com/Hjdskes/cage
We are actually getting mouse events directly from Wayland instead of going
through SDL, so we call app_updateCursorPos in pointer motion handlers and
swallow the SDL event.
Also removed parameters for app_handleMouseBasic as it relies exclusively on
absolute positions provided by app_updateCursorPos. Wayland does not give
you relative movements at all unless grabbed and passing absolute movements
is semantically incorrect.
Note that when the cursor is grabbed, movements are handled entirely through
relativePointerMotionHandler in wayland.c and does not go through
app_handleMouseBasic at all.
